Internal-combustion engine



July 31, 1 92s. 1,678,897

. E. T. ADAMS INTERNAL COMBUSTION ENGINE Filed March 15. 1923 4fnUenZ0r:Edward JaZziamq Patented July 31, 1923.

UNITED. STATES PATENT OFFICE.

EDWARD T. ADAMS, PHOENIX, ARIZONA, ASSIGNOR '10 FAIRBANKS, MORSE & 00.,OF

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

INTERNAL-COMBUSTION- ENGINE.

Application filed March 15, 1323. Serial No. 625,185.

This invention relates to .internal combustion' engines and especiallyapplies to engines adapted for burning heavy oil.

An object of this invention is to construct and dispose a preliminarychamber so as to provide a cleaner burning mixture, and to preventresidual deposits of carbon or the like.

Another object isto construct and dispose a preliminary chamber, and todeliver the fuel thereto, so as to provide in an improved manner, tworegions or zones in the chamber, one being an upper region or zone oflesser fuel concentration, and the other a lower region of greater fuelconcentration. Further objects include an improved shape of thepreliminary chambcr;' an improved arrangement for cooling the wallsthereof; novel means for maintaining temperature differences betweenregions of different fuel concentration; novel features of constructionto efiect desirable relative volumes and locations of the preliminarychamber and engine clearance space, with regard for' the pressure andamount of injected fuel; and an improved arrangement of passages between the preliminary chamber and the clearance space.

Further objects and advantages of this invention will appear from thedrawings and the following description.

I have illustrated a preferred example of the invention, in which thepreliminary chamber is of a frusto-conical shape, completely surrounded,substantially over its full length, by a water jacket, and is providedwith areplaceable liner of heat resisting -material. The advantages ofthe chamber construct-ion will be hereinafter referred to.

During operation, a more complete burning or explosion in the upperregion of the chamber, serves to deliver the remainingfuel charge fromthe lower region to the main clearance space, to be further burnedduring the working stroke of the piston.

A means for maintaining a higher term perature in the upper region, ofless fuelv concentration, is found in the conical shape of this region,which provides greater volume to be cooled, through walls of uniformthickness. Cooling of this region is further relatively retarded byrecessing, separating or otherwise insulating a portion of the outerwall of the preliminary chamber.

The example described shows the replaceable liner as provided with aplurality of relatively small passages bet-ween the preliminary chamberand the clearance space.

The passages should be large enough to allow a minimum drop invcompression pressure in the preliminary chamber, yet restricted enoughto prevent the explosive burning within the chamber from reaching theclearance space. The provision of such passages results in betterregulationof rate of burning in the clearance space, and aids in mixingthe air and fuel charge. The passages further serve to distribute fuelmixture throughout the clearance space, and prevent localized burning ofthe piston.

The passages leading to the clearance space are prevented from chokingwith carbon or the like by the close association of this part of thestructure with the water jacket. Cracking of the fuel is thus preventedat this point, and the same constricted portion of the water jacketserves to keep cool the lower, concentrated fuel region of thepreliminary chamben' Referring to the drawings, which illustratediagrammatically and merely byway of example, suitable means foreffecting the invention Fig. 1 is a sectional view of the combustion endof an internal combustion cylinder of the Diesel type, having theinvention' embodied therewith.

In Fig. 1, the combustion end of cylinder 10 is shown with thepower-piston 11, at the end of the compression stroke, leaving theclearance space 12. A conical recess 13 is provided at the top 9f thecylinder body which extends to the clearance 12. This space 13 receivesthe conical cup 14, forming the preliminary chamber 15, closed at thetop by the plate or body 16, preferably bolted to the cylinder body andcarrying the spray nozzle 17 and the channel 18 from a suitable sourceof supply, not shown. The outer peripheral wall of cup 14 is recessed asat 19, providing .a space between said cupwall and the adjacent cylinderbody wall, for the purpose to be described. At the apex of chamber 15,which, in the present example,

is at the lower end, are provided the channels or passages 20discharging from chamber i into the clearance space 12, and preferablyso inclined as to deliver the charge from v chamber 15, well distributedthroughout the clearance "'12. While I'may use to good adcal cup 14, butif desired the neck containing twenty to twenty-five per cent of thetotal volume.

clearance space into the preliminary cham-' the communicating means maybe made as a separate piece. The volume of ihe preliminary chambershould be less than one-l1a1f the total clearance, usually twenty-fiveper cent or less. l/Vhen symmetrical in form and having its length ordepth not too greatly exceeding its diameter, the, volume may be In thepreferred form, the theoretical proportion between the region of greaterfuel concentration and the region of lesser concentration, in thepreliminary chamber, is

a proximately fifty per cent. This is very t 'eoretical and considersonly the volumes within and without the cone of spray.

The conical formation of the "preliminary chamber secures orfacilitates;

1. Concentration of fuel at the small end.

2. Better cooling effect because the water jacket is brought closer tothe contents in the apex of the chamber and the passages deliveringtherefrom, thus. reducing danger of cracking the fuel, and clogging thep assages with tar and carbon.

3. Ample space for the region of lesser concentration at the base of thecon-e (in the present example at the top of the chamber).

The nature of bustible mixture in the region of lesser con- "centration,may be better understood by a consideration of the facts effecting it.

The fuel mixture in the space Without the cone of spray is formed invarious ways (a). By frlction between the surface of the cone of sprayand the dense air through which it passes; the individual articles ofspray are light and easily deflecte we might say, scraped off. I I

(b) By particles of fuel rebounding after striking the walls of thechamber;

(a) By particles of fuel carried upwards out of the .cone of spray bythe stream of heated air forced into the chamber through the channels20, bythe upward movement of the piston, at the moment when the in-'jection begins. -At this moment, the piston 15 rising and compressingair from the main ber ( 01) By the turbulence created by the in-' itialignition of the fuel, this sudden expanthe formation of the comsion ofthe is probably. an important factor.

(6) By the vaporization of fuel by contact with the heated air and byheat of combustially uniform thickness, adapted to be closely surroundedby a cooling fluid, and a closure means for said chamber.

2. In an internal combustion engine, a frusto-conical pre-combustionchamber substantially surrounded by, and uniformly separated from acooling fluid, and an injection means therein adapted to inject thegreater portion of the fuel charge-into the lower part of said chamber.

3. In an internal combustion engine, a pre-combustion chamber, a'frusto-conical liner therefor, a water jacket surrounding the sides ofsaid chamber and a means associated with said liner adapted to produce avariation in temperature between upper and lower portions ofsaidpre-combustion chamber. x

4:. In an internal combustion engine, a pre-combustion chamber, afrusto-conical liner therefor, a water jacket surrounding the sides ofsaid chamber and heat insulating means associated with said liner andadapted to produce a variation in temperature between upper and lowerportions of said pre-combustlon chamber and an injection nozzle adaptedto direct substantially the major portion of the fuel charge toward arelatively'cool portion of said pre-combustlon chamber.

5. In an internal combustion'engine, a main combustion clearance, a-pre-combustion chamber and a substantially frustoconical liner thereforforming a plurality of fuel distribution passages in the lower portionof said chamber connectin with said clearance, said lower portion ingrelatively closely surrounded by a cooling'fiuid, and an injectionnozzle adapted. substantially the major portion of the fuel chargetoward said passages.

. 6. In an oil, engine a substantially coto direct gases in a portion ofthe chamber of spray, which is g said ichamberymeans extending through athereof. 7 v e v 7. In an oil engine, a pre-combustion.

short neck between said chamber and said I clearance adapted todistribute-burning fuel over a substantial" areaof said clearance, and areplaceable liner for said pre-comcombustion chamber substantially thelength chamber and a main combustion clearance;

'li' uid cooling means about said chamber; and said clearance; saidchamber compris-L- I outer portion and a replaceable inner poringanelement adapted to contact with said cooling means and a secondelementlocated within said first named element and extend-3 in'g substantiallyt length thereof; Said elements being arranged to provide a recesstherebetween ,whereby differential heat con- 1 duction "is .efi'ected'between different portions of said elements; and a nozzle adapted ofsaid chamber.

' 8. ln an oll engine, a pre-combustlon to-inject fuel into arelativelycool 'portion chamber'and a main combustion clearance;

liquid cooling' means for said chamber and said clearance; said chambercomprising an in the lower chamber. v

9i-In an; oil engi1'1e',' "a pre-combustion chamber and a maincombustion clearance; liquid coolingmeans for {'said chamber and meansbetween said outer :and inner .por-

tionsiwherebya substantially higher temperature is maintained in theupper than said clearance;-said chamber comprising an part of saidpre-combustion tion substantially coextensive therewith, in-

a s n said pre-combust1on chamber; -a nozzle coaxial with saidchamberadapted to-inject .fuel to a relatively cool "rtion thereof;

one of th'eiportions of sai :chamber eom prising a means whereby fuel isdistributed uniformly over a .substantialarea of said mam combustionclearance.-

' EDWARD ADA S.

